1. Technical Field
This disclosure relates to an ink-jet recording apparatus which performs recording on both sides of a recording medium, and ink-jet copier employing the ink-jet recording apparatus and a recording medium used therein.
2. Description of the Related Art
A non impact recording method has taken attention recently in terms of the fact that a noise occurring at a time of recording is so small that it can be almost ignored. In this situation, a so-called ink-jet recording method is very advantageous recording medium in that a high-speed recording can be achieved, and, also, a so-called ordinary paper can be applied without necessity of any special fixing processing. Accordingly, various methods have been put into practical use after being developed and improved, while some methods are still on development so as to be put into practical use in future in the same technical field.
Such an ink-jet recording method performs recording by jetting a small drop (droplet) of a recording liquid called ink, and making it adhere to a recording medium. The ink-jet recording method may be classified into various methods with respect to a way of how to create a small drop of recording liquid or a way of controlling the direction in which the recording liquid is jetted.
For example, U.S. Pat. No. 3,060,429 discloses a Tele type, i.e., an electrostatic absorption method in which a recording liquid is absorbed electrostatically so as to create a small drop, the thus-created small drop is controlled by an electric field according to a recording signal, and, thus, is made to adhere to a recording medium selectively.
U.S. Pat. Nos. 3,596,275 and 3,298,030 discloses a Sweet type, i.e., a continuous flow type or a charge control type in which, by a continuous vibration generation method, recording liquid small drops controlled in charge amounts thereof are created, and then, the small drops controlled in charge amounts thereof are made to fly between deflection electrodes by which a uniform electric field is applied. Thereby, recording on a recording medium is achieved.
U.S. Pat. No. 3,416,153 discloses a Hertz method in which an electric field is applied between a jetting mouth and a ring-like charged electrode. Then, a continuous vibration generation method is applied so as to create a mist of recording liquid small drops, whereby recording is achieved. In this method, the electric field intensity between the jetting mouth and ring-like charged electrode is modified according to a recording signal, whereby the mist state of the small drops is controlled, and, thus, a tone variation in the recording image is created.
U.S. Pat. No. 3,747,120 discloses a Stemme method which is basically different from the above-described three methods in principle. That is, in these three methods, recording liquid small drops flying after being jetted from jetting mouths are controlled electrically, and the small drops carrying the recording signal are selectively made to adhere to a recording medium. In contrast thereto, according to the Stemme method, according to a recording signal, recording liquid small drops are jetted from jetting mouths so as to be made adhere to a recording medium. Thus, according to the Stemme method, an electric signal is applied to a piezo vibration device provided in a recording head having jetting mouths, the electric recording signal is converted into a mechanical vibration via the piezo device, and, then, according to the mechanical vibration, the small drops are jetted from the jetting mouths, which then adhere to the recording medium. Such a method is called ‘drop-on-demand type recording method’.
Japanese patent publication No. 56-9429 of the applicant of the present application discloses such a drop-on-type recording method in which, according to a recording signal, recording liquid small drops are jetted from jetting mouths, and then, recording is achieved. In this method, the ink in a liquid chamber is heated, bubbles are created in the ink, and, thanks to the function of the bubbles, ink drops are jetted from the jetting mouths. Such a method is called a bubble-ink-jet-type recording method.
As described above, there are various types in the ink-jet recording method in terms of the principle thereof. However, in any type, a common simple principle is applied in that small drops (droplets) of recording liquid, so-called ink, are jetted, and are made to adhere to a recording medium. Thereby, recently, full-scale utilization/spread of this way has become remarkable, and as a result, this method may provide an image quality which may some case become equal to that of a conventional so-called silver halide photographic image. As a result, application of this method has been studied and developed for a use not only in a printer but also for other various uses. As a part of such a trend, recently, a study has been preceded with concerning this technology in terms of resource saving, application to a copier, and so forth. However, in such a technical field, the development is merely started now, and, thus, no decisive technology has been established yet.